Fig. 4.

In MS patients with clinical relapse within the last three months (n = 10), we found significantly higher permeability in periventricular NAWM (p = 0.004), thalamic gray matter (p = 0.004), and non-enhancing lesions (NELs) (p = 0.003; two-tailed T tests) compared to those with no relapse within three months. Immunomodulatory treatment coincided with significantly lower permeability in NEL (p = 0.01; two-tailed T test). Linear regression analysis showed that treatment (Beta = − 0.021 mL/100 g/min, p = 0.039) and relapse within the last three months (Beta = 0.034 mL/100 g/min, p = 0.001) were significant predictors of permeability in MS NEL. The overall model fit was R² = 0.37 and p = 0.001 with no significant interaction between the two parameters. Values for healthy controls are added for comparison. Black line = median. Boxes = 25% and 75% percentiles. Whiskers = sample range, outliers marked by a circle. Treatment = immunomodulatory treatment with IFN-beta or glatiramer acetate. Relapse = one or more relapses within the last three months.